Desmid of the month
May 2009

Euastrum binale

Euastrum binale, in particular its var. gutwinskii, is one of the most
common desmid species in acidic, oligotrophic moorland pools and bogs. Despite
the small dimensions and a lack of conspicuous cell wall ornamentation it may
be readily recognized. Semicells are trapezoid-pyramidal in outline with a
slightly dilated apex marked by acute angles and a wide, shallow, V-shaped
median incision. Var. gutwinskii differs from the nominate variety by
having an additional lateral lobe in between the basal and the apical lobe.
Zygospores are only incidentally encountered.